This invention relates to self-propelled institutional or commercial type lawn mowers, and is especially directed to large lawnmowers intended for extended service on a daily basis by commercial landscape gardeners or ground maintenance personnel responsible for attending to lawns at corporate or government office parks, golf courses, condominiums, and the like. The invention is especially directed to walk-behind and sulky-type riding mowers in which there is an operator position situated behind the mowing mechanism.
At present, lawnmowers of this type employ belt drives both to the mower blade and to the drive wheels. In these current mowers, each wheel is belt driven and provided with a clutch and individual wheel brake which are intimately linked. The belts wear out at frequent intervals and the drive thus has a high maintenance rate. The belts also tend to slip when the grass is wet. Changing speeds requires both belts be disengaged by squeezing hand calipers found on each handle bar. A speed selector control must then be adjusted to effect speed change. Because these actions take considerable time to accomplish, the operator generally disregards making speed changes. This, however, renders precision mowing near obstacles difficult or impossible. Consequently, an intolerable amount of follow-up mowing with a hand mower or trimmer is usually required. The operator must also release his grip on the steering controls when making various machine adjustments which can and often does lead to an accident.
These same hand calipers when squeezed to their maximum position engage a brake which is used for turning purposes. Because the hand calipers are spring-controlled, they require considerable hand pressure to engage which is extremely tiring. Almost continuous squeezing is required to keep the mower steering in the proper direction due to the direct drive, non differential type axle.
Previous walk-behind mowers generally do not have a reverse speed. Because of the excessive weight of these mowers, and their uneven weight distribution, manually backing the mower is extremely tiring on the operator and oftentimes dangerous.
Also, in current mowers, a large percentage of total machine weight is carried on the front wheels in order to keep the mower deck from bouncing. As a consequence, the machine weight carried on the drive axle is less than desirable for optimum traction, especially while operating on grades.